Tossing a coin is a binomial experiment.
Now lets say there are 'n' repeated trials to get heads. Each of the trials can result in either a head or a tail.
All of these trials are independent since the result of one trial does not affect the result of the next trial.
Now, for 'n' repeated trials the total number of successes is given by

where 'r' denotes the number of successful results.
In our case
and
,
Substituting the values we get,


Therefore, there are 1352078 ways to get heads if a person tosses a coin 23 times.
The change in the water level should decrease by 1.2 inches in 24 hours.
we have

Factor the leading coefficient

Complete the square. Remember to balance the equation by adding the same constants to each side


Divide both sides by 

Rewrite as perfect squares

Taking the square roots of both sides (square root property of equality)

Remember that





<u>the answer is</u>
The solutions are

